1. Field of the Invention
The invention relates to a recliner assembly for pivotally adjusting a seat back relative to a seat cushion of an automotive vehicle seat. More particularly, the invention relates to a recliner assembly including a spring bushing for synchronizing a pair of disc recliners to unlock simultaneously and providing a lost motion connection allowing the disc recliners to lock independently.
2. Description of Related Art
Automotive vehicles include seat assemblies for supporting a seated occupant in the vehicle. The seat assemblies typically include a generally horizontal seat cushion and a generally vertical or upright seat back pivotally connected to the seat cushion by a recliner assembly. The recliner assembly allows selective pivotal adjustment of the seat back relative to the seat cushion between a plurality of reclined positions. Each of the seat cushion and seat back commonly include a rigid frame structure supporting a cellular foam pad that is encased by a fabric trim cover.
Disc recliners are well known in the vehicle seating art and are commonly used to pivotally connect the seat back to the seat cushion. Typically, disc recliners include a cylindrical outer disc fixedly secured to the seat cushion and a cylindrical inner disc fixedly secured to the seat back and rotatably coupled to the outer disc. Disc recliners further include an internal locking mechanism for locking the inner and outer discs together to thereby maintain the angular position of the seat back relative to the seat cushion. The locking mechanism typically includes an annular rim of teeth on the inner disc and several pawls each with a plurality of teeth. The pawls are movable, either slidingly or pivotally, in a radial direction between an engaged position and a disengaged position. With the pawls in the engaged position, the teeth on the pawls are interlocked or meshingly engaged with the rim of teeth on the inner disc, thus locking the inner and outer discs together and maintaining the angular position of the seat back relative to the seat cushion. When the pawls are moved from the engaged position to the disengaged position, the teeth on the pawls are spaced from the rim of teeth on the inner disc, thus allowing rotation of the inner disc relative to the outer disc and thereby providing adjustment of the seat back relative to the seat cushion.
The seat assemblies commonly include an inboard disc recliner and an outboard disc recliner which are coupled together by a rod or cross-talk tube so that only one recliner lever or release handle is required to operate the seat back. Typically, the recliner lever is coupled to the cross-talk tube adjacent the outboard recliner. Ideally, when the occupant manipulates the recliner lever to adjust the relative angle of the seat back or other desired operation of the seat back, the inboard and outboard recliners are synchronized and unlock simultaneously. Likewise, when the recliner lever is released the recliners lock simultaneously, preventing further movement of the seat back.
A problem arises when the prior art seat assemblies are manufactured and assembled. If the inboard recliner is not perfectly aligned with and extending parallel to the outboard recliner, the recliners will not be properly mounted on the cross-talk tube joining the recliners. Improper mounting causes the recliners to bind, increasing the effort required to operate the seat back. In addition, imperfect alignment of the recliners may result in the inboard recliner remaining open or unlocked after the recliner lever is released, thereby holding the outboard recliner unlocked. This situation arises when the recliner lever is released and the teeth on the pawls of the inboard recliner are in tip-to-tip or tooth-to-tooth engagement with the rim of teeth on the inner disc. In this condition, the pawls are prevented from returning to the locked position such that the inboard recliner will remain unlocked, and because the inboard and outboard recliners are joined by the cross-talk tube, the outboard recliner will also remain unlocked. Imperfect alignment is common within normal acceptable build tolerances.
In International Patent Publication Number WO2006105657 a bushing is operatively connected between a cross-talk tube and a locking mechanism of an inboard recliner. The bushing provides a lost motion connection between the cross-talk tube and the locking mechanism such that imperfect alignment of the inboard and outboard recliners does not allow the inboard recliner, when the locking mechanism is in a tooth-to-tooth condition, to hold the outboard recliner unlocked after the recliner lever is released. In other words, due to the lost motion connection the inboard and outboard recliners can lock independently.
It is desirable to provide a recliner assembly including an improved lost motion connection or spring bushing coupled between a cross-talk tube and a locking mechanism of an inboard recliner to allow the inboard recliner and an outboard recliner to lock independently and to also synchronize the inboard and outboard recliners to unlock simultaneously.